Investment objective & strategy
As of April 25, 2025 · prospectusObjective. iShares S&P 500 Index Fund (the Fund ), a series of BlackRock Funds III (the Trust), seeks to provide investment results that correspond to the total return performance of publicly-traded common stocks in the aggregate, as represented by the Standard & Poors 500 Index (the S&P 500 Index or the Underlying Index ).
Strategy. The Fund pursues its investment objective by seeking to replicate the total return performance of the S&P 500 Index, which is composed of approximately 500 selected common stocks, most of which are listed on the New York Stock Exchange (the NYSE). The S&P 500 Index is a capitalization-weighted index from a broad range of industries chosen for market size, liquidity and industry group representation. The component stocks are weighted according to the total float-adjusted market value of their outstanding shares (i.e., they are weighted according to the public float which is the total market value of their outstanding shares readily available to the general marketplace for trading purposes). The percentage of the Funds assets invested in a given stock is … The Fund pursues its investment objective by seeking to replicate the total return performance of the S&P 500 Index, which is composed of approximately 500 selected common stocks, most of which are listed on the New York Stock Exchange (the NYSE). The S&P 500 Index is a capitalization-weighted index from a broad range of industries chosen for market size, liquidity and industry group representation. The component stocks are weighted according to the total float-adjusted market value of their outstanding shares (i.e., they are weighted according to the public float which is the total market value of their outstanding shares readily available to the general marketplace for trading purposes). The percentage of the Funds assets invested in a given stock is approximately the same as the percentage such stock represents in the S&P 500 Index. The Fund is managed by determining which securities are to be purchased or sold to reflect, to the extent feasible, the investment characteristics of its benchmark index. Under normal circumstances, at least 90% of the value of the Funds assets, plus the amount of any borrowing for investment purposes, is invested in securities comprising the S&P 500 Index. The Fund is a feeder fund that invests all of its assets in the Master Portfolio of MIP, which has the same investment objective and strategies as the Fund. All investments are made at the Master Portfolio level. This structure is sometimes called a master/feeder structure. The Funds investment results will correspond directly to the investment results of the Master Portfolio. For simplicity, the prospectus uses the name of the Fund or the term Fund (as applicable) to include the Master Portfolio.
Top holdings
As of March 31, 2026 · N-PORT| Security | Ticker | Value | % of fund |
|---|---|---|---|
| U.S. Total Bond Index Master Portfolio | — | $51.32B | 100.03% |
Portfolio moves
Dec 31, 2025 → Mar 31, 2026How many positions this fund opened, exited, grew, trimmed, or left unchanged between its two most recent N-PORT snapshots — net changes between point-in-time reports, not a trade log.
Similar funds
Funds whose portfolios most overlap this one, by weight| Fund | Overlap | Net exp. |
|---|---|---|
| iShares U.S. Aggregate Bond Index Fund · WFBIX | 100% | 0.05% |
| Stock Index Fund · HSTIX | 100% | 0.48% |
| iShares Russell 1000 Large-Cap Index Fund | 100% | 0.06% |
Advisers
| Firm | Role |
|---|---|
| BlackRock Fund Advisors | Adviser |
Footnotes
- Expense ratio as of February 23, 2026, from the fund's prospectus.
- Net assets and holdings count as of March 31, 2026, from the fund's N-PORT filing.
- Total return for calendar year 2025, before tax and after fund expenses. Computed by compounding the twelve monthly total returns the fund reported in its SEC N-PORT filings for 2025 (the latest prospectus does not yet chart this year).
Machine-readable: JSON · Markdown. Programmatic access via the agent surface.